Adhesions are unwanted tissue growths occurring between layers of adjacent bodily tissue or between tissues and internal organs. Adhesions commonly form during the healing which follows surgical procedures, and when present, adhesions can prevent the normal motions of those tissues and organs with respect to their neighboring structures.
The medical and scientific communities have studied ways of reducing the formation of post-surgical adhesions by the use of high molecular weight carboxyl-containing biopolymers. These biopolymers can form hydrated gels which act as physical barriers to separate tissues from each other during healing, so that adhesions between normally adjacent structures do not form. After healing is substantially complete, the barrier is no longer needed, and should be eliminated from the body to permit more normal function of the affected tissues.
Schwartz et al (U.S. Pat. Nos. 5,906,997, 6,017,301, and 6,034,140) describe membranes, hydrogels and association complexes of carboxypolysaccharides and polyethers for use as antiadhesion compositions. Because of the presence of polyethers in membranes made using these materials, these compositions exhibited certain antithrombogenic properties, including decreased platelet adhesion, decreased platelet activation, and decreased binding of fibrin and blood clots to membranes. U.S. patent application Ser. No. 09/472,110, incorporated herein fully by reference, disclosed that multivalent cations including Fe3+, Al3+, and Ca2+, and/or polycations including polylysine and polyarginine can be used to provide intermolecular attraction, thereby providing a means of controlling viscoelastic properties of gels.
Davies et al. (U.S. Pat. No. 5,169,037 and RE35,540) describe pressurized canisters having a product bag therein.
Stoffel (U.S. Pat. No. 5,126,086) describes a pressurized container having an inner bag for delivery of product.
Obrist (U.S. Pat. No. 5,799,469) describes a method of manufacture and a pressure pack having an outer container and a bag for holding the product to be dispensed.
Patterson (U.S. Pat. No. 4,350,272) describes a barrier package having a controlled release coating that can peel from the package and form a barrier between the product and propellant.
Prior art delivery systems are depicted in FIGS. 1 and 2. FIG. 1 depicts a delivery system having a canister 100, comprising a top 103 and a bottom 118, having a bag 102 therein, to contain the product to be delivered. The bag is sealed with gusset 105, and has valve mechanism 117 with an actuator 101. The top 106 of bag 102 is shown suspended from the valve mechanism 117.
FIG. 2 depicts a prior art delivery system similar to that shown in FIG. 1, but additionally having a delivery tube 120.
There is need for improved antiadhesion products, including foams, that can be used quickly and efficiently by surgeons so as to achieve desired clinical results.